src/Pure/consts.ML
changeset 18935 f22be3d61ed5
parent 18163 9b729737bf14
child 18965 3b76383e3ab3
--- a/src/Pure/consts.ML	Mon Feb 06 20:59:01 2006 +0100
+++ b/src/Pure/consts.ML	Mon Feb 06 20:59:02 2006 +0100
@@ -2,20 +2,26 @@
     ID:         $Id$
     Author:     Makarius
 
-Polymorphic constants.
+Polymorphic constants: declarations, abbreviations, additional type
+constraints.
 *)
 
 signature CONSTS =
 sig
   type T
-  val dest: T -> {declarations: typ NameSpace.table, constraints: typ NameSpace.table}
+  val dest: T ->
+   {constants: (typ * term option) NameSpace.table,
+    constraints: typ NameSpace.table}
   val space: T -> NameSpace.T
-  val declaration: T -> string -> typ  (*exception TYPE*)
-  val constraint: T -> string -> typ    (*exception TYPE*)
-  val monomorphic: T -> string -> bool
+  val declaration: T -> string -> typ                           (*exception TYPE*)
+  val monomorphic: T -> string -> bool                          (*exception TYPE*)
+  val constraint: T -> string -> typ                            (*exception TYPE*)
+  val expansion: Type.tsig -> T -> string * typ -> term option  (*exception TYPE*)
+  val certify: Pretty.pp -> Type.tsig -> T -> term -> term      (*exception TYPE*)
   val typargs: T -> string * typ -> typ list
   val instance: T -> string * typ list -> typ
   val declare: NameSpace.naming -> bstring * typ -> T -> T
+  val abbreviate: Pretty.pp -> Type.tsig -> NameSpace.naming -> string * term -> T -> T
   val constrain: string * typ -> T -> T
   val hide: bool -> string -> T -> T
   val empty: T
@@ -25,40 +31,71 @@
 structure Consts: CONSTS =
 struct
 
-
 (** datatype T **)
 
+datatype decl =
+  LogicalConst of typ * int list list |
+  Abbreviation of typ * term;
+
 datatype T = Consts of
- {declarations: ((typ * int list list) * serial) NameSpace.table,
+ {decls: (decl * serial) NameSpace.table,
   constraints: typ Symtab.table};
 
-fun make_consts (declarations, constraints) =
-  Consts {declarations = declarations, constraints = constraints};
+fun make_consts (decls, constraints) = Consts {decls = decls, constraints = constraints};
+fun map_consts f (Consts {decls, constraints}) = make_consts (f (decls, constraints));
 
-fun map_consts f (Consts {declarations, constraints}) =
-  make_consts (f (declarations, constraints));
-
-fun dest (Consts {declarations = (space, decls), constraints}) =
- {declarations = (space, Symtab.map (#1 o #1) decls),
+fun dest (Consts {decls = (space, decls), constraints}) =
+ {constants = (space, Symtab.fold
+    (fn (c, (LogicalConst (T, _), _)) => Symtab.update (c, (T, NONE))
+      | (c, (Abbreviation (T, t), _)) => Symtab.update (c, (T, SOME t))) decls Symtab.empty),
   constraints = (space, constraints)};
 
-fun space (Consts {declarations = (space, _), ...}) = space;
+fun space (Consts {decls, ...}) = #1 decls;
 
 
 (* lookup consts *)
 
-fun the_const (Consts {declarations = (_, decls), ...}) c =
-  (case Symtab.lookup decls c of SOME (decl, _) => decl
-  | NONE => raise TYPE ("Undeclared constant " ^ quote c, [], []));
+fun err_undeclared c = raise TYPE ("Undeclared constant: " ^ quote c, [], []);
+
+fun the_const (Consts {decls = (_, tab), ...}) c =
+  (case Symtab.lookup tab c of SOME (decl, _) => decl | NONE => err_undeclared c);
+
+fun logical_const consts c =
+  (case the_const consts c of LogicalConst d => d | _ => err_undeclared c);
 
-fun declaration consts c = #1 (the_const consts c);
+fun declaration consts c = #1 (logical_const consts c);
+fun monomorphic consts c = null (#2 (logical_const consts c));
+
+fun expansion tsig consts (c, T) =
+  (case the_const consts c of
+    Abbreviation a => SOME (Envir.expand_atom tsig T a)
+  | _ => NONE);
 
 fun constraint (consts as Consts {constraints, ...}) c =
   (case Symtab.lookup constraints c of
     SOME T => T
-  | NONE => declaration consts c);
+  | NONE => (case the_const consts c of LogicalConst (T, _) => T | Abbreviation (T, _) => T));
+
+
+(* certify: check/expand consts -- without beta normalization *)
+
+fun certify pp tsig consts tm =
+  let
+    fun err msg = raise TYPE (msg, [], [tm]);
+    fun show_const (c, T) = quote c ^ " :: " ^ Pretty.string_of_typ pp T;
 
-fun monomorphic consts c = null (#2 (the_const consts c));
+    fun cert (t as Const (c, T)) =
+          (case the_const consts c of
+            LogicalConst (U, _) =>
+              if Type.typ_instance tsig (T, U) then t
+              else err ("Illegal type for constant " ^ show_const (c, T))
+          | Abbreviation (U, u) =>
+              Envir.expand_atom tsig T (U, u) handle TYPE _ =>
+                err ("Illegal type for abbreviation " ^ show_const (c, T)))
+      | cert (t $ u) = cert t $ cert u
+      | cert (Abs (x, T, t)) = Abs (x, T, cert t)
+      | cert a = a;
+  in cert tm end;
 
 
 (* typargs -- view actual const type as instance of declaration *)
@@ -67,7 +104,7 @@
   | sub T [] = T
   | sub T _ = raise Subscript;
 
-fun typargs consts (c, T) = map (sub T) (#2 (the_const consts c));
+fun typargs consts (c, T) = map (sub T) (#2 (logical_const consts c));
 
 fun instance consts (c, Ts) =
   let
@@ -77,7 +114,7 @@
 
 
 
-(** build consts **)
+(** declare consts **)
 
 fun err_dup_consts cs =
   error ("Duplicate declaration of constant(s) " ^ commas_quote cs);
@@ -85,28 +122,43 @@
 fun err_inconsistent_constraints cs =
   error ("Inconsistent type constraints for constant(s) " ^ commas_quote cs);
 
+fun extend_decls naming decl tab = NameSpace.extend_table naming (tab, [decl])
+  handle Symtab.DUPS cs => err_dup_consts cs;
 
-(* declarations etc. *)
+
+(* name space *)
 
-fun args_of declT =
+fun hide fully c = map_consts (fn (decls, constraints) =>
+  (apfst (NameSpace.hide fully c) decls, constraints));
+
+
+(* declarations *)
+
+fun declare naming (c, declT) = map_consts (fn (decls, constraints) =>
   let
-    fun args (Type (_, Ts)) pos = args_list Ts 0 pos
-      | args (TVar v) pos = insert (eq_fst op =) (v, rev pos)
-      | args (TFree _) _ = I
-    and args_list (T :: Ts) i is = args T (i :: is) #> args_list Ts (i + 1) is
-      | args_list [] _ _ = I;
-  in map #2 (rev (args declT [] [])) end;
+    fun args_of (Type (_, Ts)) pos = args_of_list Ts 0 pos
+      | args_of (TVar v) pos = insert (eq_fst op =) (v, rev pos)
+      | args_of (TFree _) _ = I
+    and args_of_list (T :: Ts) i is = args_of T (i :: is) #> args_of_list Ts (i + 1) is
+      | args_of_list [] _ _ = I;
+    val decl = (c, (LogicalConst (declT, map #2 (rev (args_of declT [] []))), serial ()));
+  in (extend_decls naming decl decls, constraints) end);
 
-fun declare naming (c, T) = map_consts (apfst (fn declarations =>
+
+(* abbreviations *)
+
+fun abbreviate pp tsig naming (c, rhs) consts =
+    consts |> map_consts (fn (decls, constraints) =>
   let
-    val decl = (c, ((T, args_of T), serial ()));
-    val declarations' = NameSpace.extend_table naming (declarations, [decl])
-      handle Symtab.DUPS cs => err_dup_consts cs;
-  in declarations' end));
+    val rhs' = Envir.beta_norm (certify pp tsig consts rhs);
+    val decl = (c, (Abbreviation (Term.fastype_of rhs', rhs'), serial ()));
+  in (extend_decls naming decl decls, constraints) end);
+
 
-val constrain = map_consts o apsnd o Symtab.update;
+(* constraints *)
 
-fun hide fully c = map_consts (apfst (apfst (NameSpace.hide fully c)));
+fun constrain (c, T) =
+  map_consts (fn (decls, constraints) => (decls, Symtab.update (c, T) constraints));
 
 
 (* empty and merge *)
@@ -114,13 +166,13 @@
 val empty = make_consts (NameSpace.empty_table, Symtab.empty);
 
 fun merge
-  (Consts {declarations = declarations1, constraints = constraints1},
-   Consts {declarations = declarations2, constraints = constraints2}) =
+  (Consts {decls = decls1, constraints = constraints1},
+   Consts {decls = decls2, constraints = constraints2}) =
   let
-    val declarations = NameSpace.merge_tables (eq_snd (op =)) (declarations1, declarations2)
+    val decls' = NameSpace.merge_tables (eq_snd (op =)) (decls1, decls2)
       handle Symtab.DUPS cs => err_dup_consts cs;
-    val constraints = Symtab.merge (op =) (constraints1, constraints2)
+    val constraints' = Symtab.merge (op =) (constraints1, constraints2)
       handle Symtab.DUPS cs => err_inconsistent_constraints cs;
-  in make_consts (declarations, constraints) end;
+  in make_consts (decls', constraints') end;
 
 end;